Marine propulsion systems

ABSTRACT

THIS INVENTION IS AN IMPROVEMENT IN MARINE PROPULSION. IT CONSISTS OF TWO FLOATS SEPARATED BY OPEN WATER AND JOINED BY INTERCONNECTING STRUCTURE. THE FLOATS ARE PROPELLED BY PRESSURIZED GASES FLOWING EXPANSIVELY WITHIN INCLINED INVERTED TROUGHING BENEATH THE FLOATS.

Sept. 21; 1911 C. T SUNDQUIST MARINE PROPULSION SYSTEMS Filed June 17, 1968 M fi l 6 m 6 4 G I. w Ill f 3 Cl 7 I f U M m ll 5 5 FIGZ . 2 If! u l S w 4 I Q 4 5 m l G F H m, N M m 9 II m m M 5 3 z G IJ v. Y H 7 L H M W H L M I w v w FIG. 6

United States Patent Oihce US. Cl. 115-11 1 Claim ABSTRACT OF THE DISCLOSURE This invention is an improvement in marine propulsion. It consists of two floats separated by open water and joined by interconnecting structure. The floats are propelled by pressurized gases flowing expansively within inclined inverted troughing beneath the floats.

This invention consists of two propulsion floats, interconnecting structure and a rudder. The floats have underwater inverted troughing inclined upwardly to the stern. Motive thrust is provided by pressurized air which expands while passing sternwardly and upwardly in the troughing.

An object of the invention is to provide a propellerless means of marine propulsion.

An object of the invention is to provide for simpler more economical propulsion machinery, in particular compact high speed rotating air compressors and gas turbines.

An object of the invention is to provide a more seaworthy marine vessel.

FIG. 1 is a plan view of a vessel employing this invention.

FIG. 2 is a side elevation of the vessel of FIG. 1.

FIG. 3 is a cross sectional view of a propulsion float taken along line 33 of FIG. 2.

FIG. 4 is a sectional view through the bow of a propulsion float taken along line 4--4 of FIG. 1.

FIG. 5 is a sectional view through the full length of a propulsion float taken along line 5-5 of FIG. 1.

FIG. 6 is a sectional view through the bow of a propulsion float taken along line 66 of FIG. 1.

In FIGS. 1 and 2 there are two propulsion floats I joined by interconnecting structures 3a and 3b. Steering is accomplished by rudder 4, which is positioned by rudder bar 5, cables 6 and winches 7.

Referring to FIG. 3, inverted troughing is formed by extending fins 17 down from the bottom of float 1. Pressurized air 18 for propulsion is trapped beneath the bottom of the float 12 and between fins 17.

Referring to FIG. 4, air for propulsion is drawn into the float through inlet stack 14. Entering gas source 15, it is pressurized and fed to plenum 16. From the plenum the pressurized air flows to the inverted troughing on the bottom of the float.

Gas source 15 is complete with a prime mover such as a gas turbine and compressor. There are gaseous products of combustion from the turbine that can be mixed with pressurized air for propulsion.

FIG. 5 illustrates how expanding gases in the inverted troughing provide propulsive thrust. A series of surface waves 19 and gas pockets 20 are formed and move sternward. Each pocket of gas expands as the pressure reduces, pushing a wave toward the stem.

The interaction of gas and water within inverted 3,606,857 Patented Sept. 21, 1971 troughing is an important consideration. The gas must be caused to react with sufficient wave surface to convert available expansion energy to propulsive effect. A nondimensional figure of merit M for this gas water interaction in a trough is expressed in the equation:

where L=length of troughing H=rise of troughing from inlet to outlet W=distance between fins The larger M the greater the fraction of available expansion energy converted. Good energy conversion is obtained when the figure of merit is 400 or more.

Referring to FIG. 3, if the fins dont extend down far enough from the bottom 12 of the float, a portion of pressurized gas flow 18 can escape from beneath the bottom of the float, wasting energy. This condition is referred to as overboarding of the pressurized gases.

Referring to FIG. 4, it is noted that bow bottom 11 is cut much higher than the bottom of the fins. In order to prevent overboarding of pressurized gases near the bow of the propulsion float, seal flapper 22 is joined to the bottom edges of the fins. See also FIG. 6'. The seal flapper is made from a flexible membrane. It fits loosely and undulates as new waves are formed.

It is not always necessary that a propulsion float have a seal flapper. In FIG. 5 bow bottom 11 is cut low enough so that overboarding of pressurized gases is less likely.

It is not advisable to use a single gas source to supply pressurized gases to the two floats. One float will inevitably lie deeper in the water or in some other way present greater resistance to gas flow than the other float. Most of the gas will follow the path of least resistance, leaving one float almost without gas. It is better to have individual gas sources for each float.

In FIG. 5 gas source 15 is arranged to pressurize the interior of float 1. The advantage of this arrangement is that if there is a small hole in the float, leakage will be outward and the float will not lose buoyancy.

In FIG. 5 the pressurized float is connected by a gas passage 23 to the inverted troughing. Thus the float acts as a pressure surge vessel to smooth the gas flow to the inverted troughing, permitting waves 19 to form in a more natural manner.

There are two places to mount equipment or store cargo in the vesselin interconnecting structure 3a or in floats 1. If the vessel is designed for offshore drilling, a drill rig would be mounted in interconnecting structure 3a. If the vessel is designed as a tanker, cargo would be stored in floats 1.

An extremely seaworthy vessel can be provided by sinking the floats deeply in the Water and reducing all structure above the water line to a streamline minimum. There would be very little excess buoyancy to help toss the vessel about in heavy seas. Wind and breaking waves would find little surface on which to exert upsetting forces.

The inventor claims:

1. A marine propulsion system comprising two floats separated by open water and joined by interconnecting structure, a source of pressurized gas, means of steering, underwater inverted troughing inclined upwardly toward the stern, and a gas passage from the float interior to in 3 4 verted troughing, whereby said gas passes sternwardly 1,861,035 5/1932 Tarn 11511 and upwardly to exert propulsive thrust. 3,191,572 6/1965 Wilson 11467(.1)X

References Cited TRYGVE M. BLIX, Primary Examiner UNITED STATES PATENTS 5 US Cl. X'R 378,613 2/1888 Olsen 114-68 114- 67A 227,323 5/1880 Tucker 1l511 

